Relay having a plurality of sealed contact switches

ABSTRACT

An industrial relay having a plurality of hermetically sealed contact switches included therein. The relay includes a U-shaped ferromagnetic structure having a base portion and two leg portions extending from the base portion, wherein the distal ends of each of the leg portions form oppositely disposed first and second pole faces. An energizing coil is positioned around one of the legs of the U-shaped structure. A plurality of sealed contact switches, each having a respective glass housing positioned flush against the pole faces of the structure, are permanently bonded to the pole faces. The above described components are containable in a suitable enclosure.

United States Patent 2 1191 Guichard 1111 3,840,831 1' Oct. 8, 1974 RELAY HAVING A PLURALITY' OF SEALED CONTACT SWITCHES [75] Inventor: Robert Charles Guichard, Normal,

Ill.

[73] Assignee: General Electric Company, New

York, NY.

[22] Filed: Sept. 26, 1973 [21] Appl. No.: 400,903

[52] US. Cl. .1 335/152, 335/153 [51] Int. Cl. H0lh 51/22 [58] Field of Search 335/151, 152, 153, 154

[56] References Cited UNITEDSTATES PATENTS 2,987,593 6/1961 Alley 335/154 3,222,758' 12/1965 Marks 335/153 X 3,254,171 5/1966 Freeland et al 335/152 Primary Examiner-R. N. Envall, Jr. Attorney, Agent, or FirmS. A. .Young; P. L. Schlamp; R. G. Simkins [57] ABSTRACT An industrial relay having a plurality of hermetically sealed contact switches included therein. The relay includes a U-shaped ferromagnetic structure having a base portion and two leg portions extending from the base portion, wherein the distal ends of each of the leg portions form oppositely disposed first and second pole faces. An energizing coil is positioned around one of the legs of the U-shaped structure. A plurality of sealed contact switches, each having a respective glass housing positioned flush against the pole faces of the structure, are permanently bonded to the pole faces. The above described components are containable in a suitable enclosure.

8 Claims, 5 Drawing Figures smzn ear 2 PATENTEUUCT 81974 RELAY HAVING A PLURALITY OF SEALED CONTACT SWITCHES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relatesto relays and more particularly to relays having a plurality of sealed contact switches included therein.

2. Description of the Prior Art Industrial relays which have a plurality of sealed contact reed switches positioned in the proximity of the pole faces of U-shaped magnetic structures have been previously manufactured. More specifically such a relay has been described in US. Pat. No. 3,605,049 wherein a plurality of flux fingers are shown as positioned over the pole faces of a U-shaped magnet to form a plurality of separate channels for receiving the sealed contact reed switches. However these flux fingers, which are used for facilitating the location and positioning of the sealed contact switches within the relay, cause an increase in the overall dimensioning of the final relay, since the side walls of these flux fingers as shown in FIG. 3 of the above referred to patent extend considerably upward from the pole faces. Furthermore the use of flux fingers and the time required for positioningthem within the relay during assembly adds to the cost of materials and labor, and thus makes the relay more expensive. Still further, the upwardly extending walls of the flux fingers cause the lines of flux to spread out so thatthey are not significantly concentrated at the air gap of the reed switches. This effectively causes an undesirable decrease in the sensitivity of the relay for-a' given coil burden, and in order to maintain a specified degree of sensitivity, the current carrying capacity of the coil and the actual coil burden would have to be relatively large, so that the final relay is relatively large in size and expensive.

, OBJECTS OF THE INVENTION It is therefore an object of this invention to provide an improved industrial relay having a plurality of sealed contacts, wherein the relay has none of the aforementioned disadvantages.

It is another object of this invention to'provide an improved more compact and less expensive relay having a plurality of sealed contacts.

It is a further object of this invention to provide an improved industrial relay having a plurality of sealed contacts wherein there is a decrease in the coil burden for a specified degree of switching sensitivity.

Other objects of the invention will be pointed out in and understood from the following.

SUMMARY OF THE INVENTION In accordance with a broad aspect of the invention there is provided an improved relay comprising a plurality of sealed reed switches; A coil is positioned around the base of a U-shaped ferromagnetic structure. A pair of legs extend from the base of the structure, and

those ends of the respective legs distal from the base form respective pole faces for the structure when the coil is energized A plurality of the sealed reed switches have their respective housings positioned in direct contact with the pole faces of the structure and permanently bonded thereto. Each of the sealed switches inwithin its housing wherein overlapping ends of the reed members define a gap therebetween. Each of the respective switches is positioned on both the pole faces such that its reed members are approximately parallel to the plane of thepole faces, and a gap defined by the overlapping pair of reed members therein is spaced approximately equidistant from both pole faces. Each switch further includes a spring member attached to one of the reed members and the switch is so positioned on the pole faces of the structure that the other of the reed members is normally located closer to the pole faces than is the spring member.

cludes a pair of magnetic reed members extending BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is afront view of a relay showing a sealed contact switch fixed to the pole faces of a U-shaped magnetic structure FIGS. 2 and 3 are respective end and top views of the relay depicted in FIG. 1, wherein it is more clearly shown that there are a plurality of scaled contact reed switches positioned on and affixed to the pole faces of the U-shaped magnetic structure;

FIG. 4 is a front view of another embodiment of the relay shown in FIG. 1, wherein the relay further includes a biasing bar magnet attached to one of the sealed contact switches to convert that switch to a normally closed switch when the relay is deenergized; and

FIG. 5 is an electrical circuit representation of the relay and one of its sealed contact switches.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1 through 3 a relay 10 is comprised of a U-shaped ferromagnetic structure 12, an energizing coil 14 and a plurality of scaled contact reed switches 16. Structure 12 is made of any suitable. magnetic material such as laminated silicon steel, and has first and second respective legs 18 and 20 extending at right angles from a base portion 22. That end of leg 18 distal from base portion 22 has aflat end surface which defines a first pole face 24, and that end of leg20 distal from base portion 22 has a flat end surface defining a second pole face 26 whichis in the same plane of extension as the plane of pole face 24.

Energizing coil 14 has a slot 28 therein shown in FIG. 3 so that in assembly leg 18 can be passed through slot 28 until a portion of a bottom surface 30 of coil.14 abuts a portion of a top surface 32 of base portion 22. Energizing coil 14 has terminals 34 and 36 electrically connected to its internal coil windings which surround leg. 18 in such'a manner that when a source of direct current enters terminal 34 and exits terminal 36, a magnetic flux field is so established that magnetic flux exits pole face 24 and enters pole face 26. Under these circumstances pole face 24 is established as the north magnetic pole and pole face 26 is established as the south magnetic pole of the electromagnet formed upon energization of coil 14. Alternatively if direct current enters terminal 36 and exits terminal 34 of coil 14, pole 38 of each of the sealed contact switches is positioned flush against and permanently attached to both pole faces using a suitable bonding agent. Housing 38 in this embodiment is formed of glass. One such suitable bonding agent for affixing the glass housing to the metal pole faces, and which cures almost instantaneously, is a methyl acrylic compound sold under the brand name Eastman 910 adhesive and manufactured by the Chemicals Division of the Eastman Kodak Company. Another suitable bonding agent for this purpose, and which also cures almost instantaneously, is a two part product made by CIBA Products Company, the first part being Araldite epoxy resin 6004 and the second part being an Araldite hardener 956, wherein the proportion of resin to hardener is to 1.

Sealed contact switches 16 are of the same type and construction and operate in the same manner as the switches described in my copending US. Pat. application Ser. No. 345,997 filed Mar. 29, 1973 and assigned to the assignee of the present invention. To the extent necessary to understand the present invention switch 16 will be briefly described as follows. As shown in FIG. 1, each switch includes first and second respective magnetic reed members 40 and 42, wherein one end 44 of reed member 40 is positioned externally of housing 38 and the other end 46 of member 40 is positioned within housing 38, and one end 48 of member 42 is positioned externally of housing 38 and the other end 50 of member 42 is positioned within housing 38. Innermost ends 46 and 50 of respective reed members 40 and 42 are overlapping, and when relay coil 14 is deenergized, ends 46 and 50 are spaced apart to define a gap whereby the reed switch is opened. For optimum performance the gap formed between overlapping ends 46 and 50 of respective reed members 40 and 42 is located approximately equidistant between respective pole faces 24 and 26 of U-shaped structure 12. Furthermore, reed members 40 and 42 are positioned approximately parallel to the plane of pole faces 24 and 26.

Each of the switches further includes a contact button 52 attached to reed member 40 adjacent end 46. One end 54 of a silver spring 56 is fastened to reed member 42 while the other end of spring 56 extends beyond end 50 of reed member 42 and has a contact button 58 attached thereto and in juxtaposition with contact button 52. Again for optimum performance member 40 is positioned closer to the pole faces of structure 12 than is silver spring 56. While spring 56 is preferably formed of silver, any nonmagnetic spring material having similar properties and characteristics can be used.

The relay can be mounted in a suitable enclosure (not shown) of any convenient standard type such as those illustrated in US. Pat. No. 3,605,049 and 3,593,231 wherein terminals 34 and 36 of coil 14 and ends 44 and 48 of the sealed contact switches are conventionally electrically connected to the external terminals of the relay enclosure (not shown).

By directly bonding sealed contact switches 16 to pole faces 24 and 26 of U-shaped structure 12, the finally assembled relay is made more compact, and since less components are used than were previously used in the prior art device described in U.S. Pat. No. 3,605,049, the cost of manufacturing the product is also reduced. Furthermore the above described structure provides that the magnetic flux .path of the relay is more directly concentrated at the gap between overlapping ends 46 and 50 of respective members 40 and 42, thereby reducing the coil burden of the energizing coil for a specified relay sensitivity so that the coil and ultimately the relay is reduced in size.

While the sealed contact switches shown in FIGS. 1 through 3 are all of the normally open type when coil 14 is deenergized, one or more of the sealed contact switches can be converted to the normally closed mode in the following manner, as shown in FIG. 4, when the coil is deenergized. A permanent bar magnet 60 is bonded to the housing of any of those sealed contact switches which are to be converted to the normally closed contact mode. The bonding agent used to attach magnet 60 to glass housing 38 of the sealed contact switch can be identical to the previously described bonding agents used to affix the sealed contact switches to the pole faces of U-shaped structure 12. Bar magnet 60 is so positioned that its north magnetic pole is oriented opposite the south magnetic pole of the electromagnet formed by energized coil 14 and structure 12, while the south magnetic pole of bar magnet 60 is oriented opposite the north magnetic pole of the electromagnet. Thus, in operation when coil 14 is deenergized, the magnetic flux, which flowsfrom the northmagnetic pole to the south magnetic pole of bar magnet 60, passes through the magnetic reed members and provides sufficient force to cause the overlapping ends of the magnetic reed members to be in contact so that the switch is in the normally-closed condition. Upon energization of the relay and the flow of current through coil 14, pole face 24 is established as north magnetic pole and pole face 26 is established as south magnetic pole, and magnetic flux flows therebetween and interacts with the opposing magnetic flux from bar magnet 60. The resultant flux field flowingthrough the magnetic reed members is then insufficient to keep the overlapping ends of the reed members in contact and the sealed switch is biased to the open condition. Upon deenergization of the relay the magnetic field between the pole faces of U-shaped structure 12 collapses so that the resultant magnetic field flowing between the poles of bar magnet 60 and throughthe magnetic reed members is again sufficient to cause the closing of the sealed contact switch.

Referring to the electrical equivalent circuit of the relay shown in FIG. 5, another feature of the invention will now be explained. It should be noted that while the electrical equivalent of only one sealed contact switch is represented in FIG. 5, four sealed contacts are actually provided. As explained above, one end of the winding of coil 14 is connected to terminal 34 and the other end of its winding is connected to terminal 36. Direct current flows into terminal-34 and flows-out of terminal 36 by having terminal 34 electrically connected to a first output terminal 62 of a full wave rectifierbridge 64 and having terminal 36 electrically connectable to a second output terminal 66 of bridge 64. A first'input terminal 68 of bridge 64 is electrically connectable to a first terminal 70 of an AC sourceof power, while asecond input terminal 72 of bridge 64 is electrically connectable to a second terminal 74 of the AC power source. Full wave rectifier bridge 64 is comprised of four rectifiers 76, 78, and 82 which. are intercon nected in the standard fashion. For example, the anodes of rectifiers 80 and 82 are connected to output terminal 66 and the cathodes of rectifiers 76 and 78 are connected to output terminal 62, while the anode of retifier 76 and the cathode of rectifier 82 are connected to input terminal 68, and the anode of rectifier 78 and the cathode of rectifier 80 are connected to input terminal 72 of bridge 64. In order to prevent excessive voltage transients from the AC power source, which would be applied across input terminals 68 and 72 of bridge 64, from causing irreparable damage to any of the rectifiers of the bridge, which damage could cause. failure of the overall relay, voltage transient suppression means 84 is placed across input terminals 68 and 72 of bridge 64. One such suitable type of voltage transient suppression means can be provided by use of a suitable metal oxide varistor such as a GE. MOV Type VP Varistor sold by the General Electric Company. lt, of course, should be noted that bridge 64 and voltage transient suppression means 84 can be mounted onto a printed circuit card which is positioned internally of the overall enclosure for the relay (not shown) and terminals 70 and 74 can be externally positioned on the exterior of the relay enclosure (not shown) to provide convenient electrical interconnection with the AC. power source.

Although the invention has been described with reference to specific embodiments thereof, numerous modifications are possible without departing from the invention and it is desirable to cover all modifications falling within the spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A relay comprising:

a. a ferromagnetic structure having a base and at least first and second leg portions extending from said base to form a U-shaped configuration therewith, the distal ends of said first and second leg portions having first and second respective pole faces, both of said pole faces extending into the same single flat plane;

b. an energizing coil positioned around a portion of said structure; and 1 c. a plurality of sealed contact switches, each of said switches including an insulative housing positioned directly against and attached to both of said pole faces.

2. A relay according to claim 1, wherein each of said sealed contact switches are further comprised of:

a. a first magnetic reed member having one end extending within said housing;

b. a first contact button fixed adjacent said one end of said first magnetic reed member;

c. a second magnetic reed member having one end extending within said housing and overlapping said one end of said first magnetic reed member;

(1. a non-magnetic spring having one end attached to said second member within said housing and another end extending beyond the overlapping ends of the first and second magnetic reed members; and

e. a second contact button attached to said other end of said spring, said second contact button being in juxtaposition with said first contact button.

3. A relay according to claim 2, wherein said magnetic reed members are positioned approximately parallel to said first and second pole faces of said U-shaped structure.

4. A relay according to claim 2, wherein the overlapping ends of said magnetic reed members define a gap therebetween, said gap being approximately equidistant between said respective first and second pole faces.

5. A relay according to claim 2, wherein said first magnetic reed member is positionedcloser to said pole faces than is said second magnetic reed member.

6. A relay according to claim 1, further comprising a bar magnet attached to a portion of the surface of said housing of one of sealed switches whereby said'one switch is adapted to operate in a normally closed mode when said coil is deenergized.

7. A relay according to claim 1, wherein said plurality of switches are permanently bonded to said pole faces;

one switch.

. 2 2 3 STATES PATENTQFFICE I v C,ERTIFICATE 0F CORRECTION Patent No. 3, 40, 31 Dated Ocfi'ober 8, 1974 Inventqr Robert C Guichard It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim- 6, line 3, before "sealed" insert said Signed a n i sealed this 17th day of December 1974.

(SEAL) Attest: I

0 JR. C. MARSHALL DANN A ggs t i og iiger Commissioner of Patents 

1. A relay comprising: a. a ferromagnetic structure having a base and at least first and second leg portions extending from said base to form a Ushaped configuration therewith, the distal ends of said first and second leg portions having first and second respective pole faces, both of said pole faces extending into the same single flat plane; b. an energizing coil positioned around a portion of said structure; and c. a plurality of sealed contact switches, each of said switches including an insulative housing positioned directly against and attached to both of said pole faces.
 2. A relay according to claim 1, wherein each of said sealed contact switches are further comprised of: a. a first magnetic reed member having one end extending within said housing; b. a first contact button fixed adjacent said one end of said first magnetic reed member; c. a second magnetic reed member having one end extending within said housing and overlapping said one end of said first magnetic reed member; d. a non-magnetic spring having one end attached to said second member within said housing and another end extending beyond the overlapping ends of the first and second magnetic reed members; and e. a second contact button attached to said other end of said spring, said second contact button being in juxtaposition with said first contact button.
 3. A relay according to claim 2, wherein said magnetic reed members are positioned approximately parallel to said first and second pole faces of said U-shaped structure.
 4. A relay according to claim 2, wherein the overlapping ends of said magnetic reed members define a gap therebetween, said gap being approximately equidistant between said respective first and second pole faces.
 5. A relay according to claim 2, wherein said first magnetic reed member is positioned closer to said pole faces than is said second magnetic reed member.
 6. A relay according to claim 1, further comprising a bar magnet attached to a portion of the surface of said housing of one of sealed switches whereby said one switch is adapted to operate in a normally closed mode when said coil is deenergized.
 7. A relay according to claim 1, wherein said plurality of switches are permanently bonded to said pole faces.
 8. A relay according to claim 6, wherein said bar magnet is permanently bonded to said housing of said one switch. 